The nucleus of an atom of every element will always contain____________________?
A. neutrons
B. protons and electrons
C. protons
D. protons and neutrons
Which of the following methods is used to estimate hydrogen in an organic compound ?
A. Combustion method
B. Dumas method
C. Kjeldahls method
D. All of the above methods are for different purposes
Isotopes differ in_________________?
A. properties which depend upon mass
B. arrangement of electrons in orbitals
C. chemical properties
D. all of the above
Combustion analysis is performed to determine__________________?
A. Empirical formula
B. Molecular mass
C. Molecular formula
D. Formula mass
Qualitative analysis is carried out for _________________?
A. identification of elements
B. estimation of amounts of elements
C. molar ration of elements
D. molar volume of elements
Which of the following statements is wrong about isotopes ?
A. they possess different mass number
B. they possess different physical properties
C. they possess same chemical properties
D. they possess different position in the periodic table
The mass of decimole of electrons (NA) is___________________?
A. 1.008 mg
B. 0.184 mg
C. 0.054 mg
D. 5.4 mg
Which one of the following is not the mono isotopic element ?
A. arsenic
B. uranium
C. iodine
D. nickel